BioLegend's Nuclear Factor Fixation and Permeabilization Buffer Set has been specially formulated for staining of nuclear and other intracellular antigens with minimum effect on the surface fluorochrome staining. It contains one 30 ml 4X concentrated Nuclear Factor Fixation Buffer and one 25 ml 10X concentrated Nuclear Factor Permeabilization Buffer. The Nuclear Factor Fixation Buffer (4X) must be freshly diluted to 1X working solution with PBS.Caution: The Nuclear Factor Fixation Buffer contains paraformaldehyde, which is toxigenic and mutagenic. Please handle with caution and wear gloves, lab coat, and necessary protection to avoid direct body contact.